Anderson Corey L, Langer Emma R, Routes Timothy C, McWilliams Seamus F, Bereslavskyy Igor, Kamp Timothy J, Eckhardt Lee L
Department of Medicine, University of Wisconsin-Madison, Madison, WI, 53705, USA.
Cellular and Molecular Arrhythmias Research Program, University of Wisconsin-Madison, Madison, WI, 53705, USA.
NPJ Genom Med. 2021 Dec 3;6(1):103. doi: 10.1038/s41525-021-00265-x.
Hundreds of LMNA variants have been associated with several distinct disease phenotypes. However, genotype-phenotype relationships remain largely undefined and the impact for most variants remains unknown. We performed a functional analysis for 178 variants across five structural domains using two different overexpression models. We found that lamin A aggregation is a major determinant for skeletal and cardiac laminopathies. An in vitro solubility assay shows that aggregation-prone variants in the immunoglobulin-like domain correlate with domain destabilization. Finally, we demonstrate that myopathic-associated LMNA variants show aggregation patterns in induced pluripotent stem cell derived-cardiomyocytes (iPSC-CMs) in contrast to non-myopathic LMNA variants. Our data-driven approach (1) reveals that striated muscle laminopathies are predominantly protein misfolding diseases, (2) demonstrates an iPSC-CM experimental platform for characterizing laminopathic variants in human cardiomyocytes, and (3) supports a functional assay to aid in assessing pathogenicity for myopathic variants of uncertain significance.
数百种LMNA基因变体与几种不同的疾病表型相关。然而，基因型与表型之间的关系在很大程度上仍不明确，大多数变体的影响尚不清楚。我们使用两种不同的过表达模型对五个结构域中的178个变体进行了功能分析。我们发现核纤层蛋白A聚集是骨骼和心脏核纤层蛋白病的主要决定因素。体外溶解度分析表明，免疫球蛋白样结构域中易于聚集的变体与结构域不稳定相关。最后，我们证明，与非肌病性LMNA变体相比，肌病相关的LMNA变体在诱导多能干细胞衍生的心肌细胞（iPSC-CM）中显示出聚集模式。我们的数据驱动方法（1）揭示横纹肌核纤层蛋白病主要是蛋白质错误折叠疾病，（2）展示了一个用于表征人类心肌细胞核纤层蛋白病变体的iPSC-CM实验平台，并（3）支持一种功能测定法，以帮助评估意义不确定的肌病性变体的致病性。
